Hemophilia A F8 Gene, Intron 1 and 22 Inversion Mutation Analysis, Blood
Use
This test is primarily useful for identifying common inversion variants within the F8 gene associated with severe hemophilia A. Approximately 50% of affected male patients with severe hemophilia A present these inversions, while it is used for determining carrier status among at-risk females with a family history of severe hemophilia A. It serves as the first-tier molecular testing for male patients with severe hemophilia A when a familial variant has not been identified.
Special Instructions
It is highly recommended to confirm the F8 inversion variant in an affected male patient or obligate female carrier before proceeding to test at-risk individuals. For cases involving postnatal umbilical cord blood specimens, it's necessary to pair with a maternal whole blood specimen to complete maternal cell contamination studies.
Limitations
This assay is designed to detect only F8 intron 1 and 22 inversion variants, thus a negative outcome does not rule out other F8 variants. Additionally, this test may not be informative for a fraction of families due to its specificity toward certain inversion variants present in only about 50% of individuals with severe hemophilia A. Any results should be interpreted alongside other clinical data, family history, and laboratory results.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 81761-9
- 42349-1
- 81761-9
- 69047-9
- 18771-6
Result Turnaround Time
14-21 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
4 mL
Minimum Volume
1 mL
Container
Lavender top (EDTA); acceptable: Yellow top (ACD) or blue top (3.2% sodium citrate)
Collection Instructions
Invert several times to mix blood. Send whole blood specimen in original tube.
Patient Preparation
A previous bone marrow transplant from an allogeneic donor will interfere with testing.
Causes for Rejection
Specimens with gross hemolysis or lipemia are acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 7 days |